Communication of messages over a network has become a part of everyday life. For example, users may communicate, one to another, through the use of email, i.e., electronic mail. Email employs standards and conventions for addressing and routing such that the email may be delivered across a network, such as the Internet, utilizing a plurality of devices. In another example, users may communicate, one to another, through the use of instant messaging. When two users are online at the same time, for instance, instant messages may be exchanged in real time between the two users. In this way, the instant messages may be utilized to support a text conversation between the two users in a manner that mimics how the two users would participate in a typical spoken conversation.
Unfortunately, the popularity of network communication using messages has also resulted in a corresponding increase in the amount of “spam” encountered by the user. An example of “spam” is an unsolicited email that is sent to a large number of recipients, such as to promote a product or service. Because sending an email generally costs little or nothing to send, “spammers” have developed which send the equivalent of junk mail to as many users as can be located. Even though a minute fraction of the recipients may actually desire the described product or service, this minute fraction may be enough to offset the minimal costs encountered by the spammer in sending the spam. Consequently, a vast number of spammers are responsible for communicating a vast number of unwanted and irrelevant emails. The communication of spam results in significant costs to email providers as well as recipients of email that are forced to navigate through these unwanted and unsolicited messages.
One technique that may be utilized to combat spammers is through the use of “digital signatures”. A digital signature (hereinafter also referred to as a “signature”) may be used to authenticate an identity of the sender of a message. Therefore, the digital signature may be utilized to verify a source of a message and combat spammers who desire to hide their identity. However, computation of a digital signature may be costly in terms of processing resources. Therefore, a service (e.g., an email service) which desires to provide a digital signature for each of a multitude of messages sent by the service may be confronted with significant hardware, software and network costs to provide the signatures.
Therefore, there is a continuing need for improved techniques that may be utilized to provide signatures.